EP2184979B1 - Method for controlling protozoa that harbor bacteria - Google Patents

Method for controlling protozoa that harbor bacteria Download PDF

Info

Publication number
EP2184979B1
EP2184979B1 EP08756423.3A EP08756423A EP2184979B1 EP 2184979 B1 EP2184979 B1 EP 2184979B1 EP 08756423 A EP08756423 A EP 08756423A EP 2184979 B1 EP2184979 B1 EP 2184979B1
Authority
EP
European Patent Office
Prior art keywords
protozoa
biocide
legionella
bacteria
aqueous system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP08756423.3A
Other languages
German (de)
French (fr)
Other versions
EP2184979A1 (en
Inventor
Wilson Kurt Whitekettle
Gloria Jean Tafel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BL Technologies Inc
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Publication of EP2184979A1 publication Critical patent/EP2184979A1/en
Application granted granted Critical
Publication of EP2184979B1 publication Critical patent/EP2184979B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
    • A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
    • A01N25/26—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests in coated particulate form
    • A01N25/28—Microcapsules or nanocapsules
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/30—Against vector-borne diseases, e.g. mosquito-borne, fly-borne, tick-borne or waterborne diseases whose impact is exacerbated by climate change

Definitions

  • the field of the invention relates to methods for controlling protozoa trophozoites that carry or harbor bacteria in aqueous systems. More particularly, embodiments of the present invention relate to methods for controlling bacteria engulfed within protozoa in the amoeboid form, including the bacterium Legionella pneumophila.
  • Intracellular bacterial pathogens that is bacterial pathogens that inhabit another cell or microorganism, are a major cause of human morbidity and mortality. Evading hostile intracellular environments is one of the ways pathogens can live within a host cell, grow symbiotically or parasitically within host cells, and yet not be killed or inhibited by the host cell. These parasites have developed ways of interacting and overcoming the host cells natural defense mechanisms.
  • Legionella pneumophila a bacterium known to cause Legionnaire's Disease and Pontiac fever in humans is a parasite of this type. While the Legionella cells can be killed readily if exposed to certain chemical agents and antibiotics, Legionella can also be found engulfed (phagocitized) within certain protozoa hosts. Legionella are often found in biofilms adsorbed to solid surfaces in, for example, water distribution systems, cooling towers, showers, aquaria, sprinklers, spas, and cleaning baths. Protozoa are natural grazers on surfaces and engulf and digest bacteria as part of their natural life cycle.
  • the protozoa digest these bacteria through the use of digestive enzymes in their phagosomes (digestive vacules). In the case of Legionella, however, this is not the case.
  • the protozoa are not readily capable of degrading the engulfed Legionella cells, and in fact the Legionella grow and increase their numbers while protected within protozoa phagosomes.
  • Legionellosis in humans can be contracted by breathing Legionella aerosols containing either the free-living bacterial cells or by inhaling aerosols of Legionella concentrated within susceptible protozoa.
  • a Legionella control agent therefore, must be capable of killing free-living Legionella, Legionella within protozoa, or the protozoa themselves.
  • the agents described in this invention are capable of killing the free-living Legionella and the host protozoa.
  • Two protozoa species capable of harboring infectious Legionella are Acanthamoeba and Tetrahymena.
  • Certain protozoa particularly amoeboid forms, have evolved mechanisms for surviving in hostile environments. Examples of hostile environments are high temperature, desiccation, presence of chemical agents/antibiotics, lack of food sources, etc. Upon encountering a hostile environment, these protozoa revert to a cyst form that is very difficult to kill. The cyst form becomes much less susceptible to chemical agents that readily kill the same organism when it is in non-cyst (trophozoite) form.
  • a chemical control agent to eliminate Acanthamoeba can actually provide the hostile environment to which the protozoa responds by reverting to a cyst form, thereby rendering it invulnerable to the chemical agent.
  • the cyst contains the pathogen Legionella
  • the chemical agent can no longer reach the engulfed bacteria, and the chemical treatment is rendered ineffective.
  • chlorination or bleach is considered essential to control Legionella in water distribution systems. Exposed Legionella are readily killed by low levels of free chlorine (0.2-0.5 ⁇ g/ml).
  • Infective Legionella can also be contained in Acanthamoeba phagosomes if those protozoa are present.
  • the Acanthamoeba sensing the chlorine presence, reverts to a cyst form, inadvertently preserving and protecting the Legionella parasites engulfed within it.
  • the Acanthamoeba cysts treated with > 500 times (>100 ⁇ g/ml "free" chlorine) the concentration needed to kill the trophozoite forms are not killed in the cyst form.
  • the cysts can revert to the active trophozoite form upon removal of the oxidant.
  • 6,579,859 discloses the use of phosphonium salts of the general formula (R 1 ) 3 P + R 2 ⁇ X - wherein R 1 is an alkyl group of from 1 to 8 carbon atoms, R 2 is an n-alkyl group giving 8 to 20 carbon atoms and X is an anion consisting of a halide, sulfate, nitrate, nitrite, etc.
  • US patent publication no. 2005/002710 teaches the exposure of the protozoa to quaternary ammonium salts, while US patent publication no. 2005/0080142 discloses the use of guanidine or biguanidine salts to control Legionella type bacteria in the free-living state as well as when engulfed in the trophozoite form or Acanthamoeba in cyst form.
  • a method of destroying protozoa trophozites is provided according to claim 1.
  • the present invention relates to methods for controlling protozoa trophozoites that carry or harbor bacteria in aqueous systems. More particularly, embodiments of the present invention relate to methods for controlling bacteria engulfed within protozoa in the amoeboid form, including the bacterium Legionella pneumophila.
  • Biocides is intended to include, but not be limited to biocides, biocide compositions, killing agents, control agents, and combinations thereof.
  • One embodiment provides a method for controlling protozoa trophozites which comprises encapsulating a biocide, killing agent or control agent in a micro-capsule or nano-capsule, and then introducing the micro-capsule or nano-capsule into an aqueous system in effective amounts.
  • the microcapsules or nano-capsules are produced and applied in effective sizes, that is of a size to be phagocytized by protozoa, such as from about 0.025 to about 10 microns.
  • the micro-capsule or nano-capsule is produced such that is has an exterior composition adapted for digestion by said protozoa.
  • Aqueous systems include, but are not limited to, water distribution systems, cooling towers, showers, aquaria, sprinklers, spas, and cleaning baths.
  • the biocide or agent is contained within an aqueous liposome core or trapped within the hydrophobic lipid layers. Thereafter, the liposomes are introduced into an aqueous system.
  • the liposomes are the encapsulating bodies containing the biocide, or such a biocide-containing liposomes may themselves be further encapsulated, e.g., by a thin shell of protective material.
  • the shell may, for example, be compounded to provide a further, temporary protective cover for the liposome, such as a degradable skin, that enhances the lifetime of the liposome in the water system yet dissolves, decays or otherwise breaks down after a certain time, or under certain conditions, releasing the liposomes which may then act on the target organisms.
  • a further, temporary protective cover for the liposome such as a degradable skin
  • Effective amounts of the biocide containing microcapsule or liposome is introduced into an aqueous system containing infected protozoa.
  • the active protozoa, the trophozoite stage then grazes on the microcapsules or liposomes, mistaking them for bacteria cells.
  • the natural enzymatic breakdown of the biocide containing microcapsule or liposome by the protozoa would result in the release of the biocide, killing agent or control agent in high concentration in the protozoa, in direct proximity to the engulfed Legionella. Rapid Legionella death would then proceed.
  • the benign surface structure of the liposome is additionally advantageous in that, unlike a traditional control agent, it should not induce cyst formation, creating more barriers to treatment.
  • the ability of encapsulated control agents to specifically be taken up by and target the protozoa is expected to allow a relatively low concentration of treatment material to be added to a fluid system yet be more highly effective than the use of free biocide, whose efficacy depends on its level in the fluid as a whole.
  • Effective amounts of the biocide containing microcapsule or liposome would depend on the biocide or agent incorporated therein. However effective amounts include from about 0.05 to about 500 micrograms per milliliter, or alternately about 0.1 to about 100 micrograms per milliliter.
  • Liposomes which are systems in which lipids are added to an aqueous buffer to form vesicles, structures that enclose a volume, may be manufactured by any known process. Such processes may employ, but are not limited to, injection, extrusion (for example pressure extrusion of an aqueous biocide through a porous membrane into the lipid body or vice-versa), sonication, microfluid processors and rotor-stator mixers.
  • the biocide containing liposomes should be produced in sizes that mimic bacterial cells, from about 0.05 to about 15 ⁇ , or alternately, about 0.1 to 10.0 ⁇ .
  • the agent may encapsulated within other oil or oil-like phases by known encapsulation processes, so as to have one or more protective outer layers that define the microcapsule lifetime, delivery characteristics and use environment.
  • guanidine or biguanidine salts examples include, but not limited to guanidine or biguanidine salts, quaternary ammonium salts and phosphonium salts.
  • guanidine or biguanidine salts are of the general formulas : or or wherein R, R 1 , R 2 are independently H, C 1 -C 20 substituted or non-substituted alkyl (linear or branched) or aryl, X is an organic or inorganic acid, n is 0-20 and z is 1-12.
  • Examples of the general formula of acceptable phosphonium salts comprises (R 1 ) 3 P + R 2 ⁇ X - wherein R 1 is an alkyl group of from 1 to 8 carbon atoms, R 2 is an n-alkyl group giving 8 to 20 carbon atoms and X is an anion consisting of a halide, sulfate, nitrate, nitrite, and combinations thereof.
  • R 1 is an alkyl group having from 1-8 carbons
  • R 2 is an n-alkyl group having 6-20 carbon groups
  • X - is an anion such as halides, sulfates, nitrates, nitrites and mixtures thereof.
  • X - is chloride, bromide, iodide, SO 4 2- , and NO 3 - , NO 2 - or mixtures thereof.
  • R1 and R2 are hydroxyalkyl groups having from 1-4 carbons and X - is an anion such as halides, sulfates, nitrates, nitrites and mixtures thereof.
  • Quaternary ammonium salts are another example of a biocide or agent that may be encapsulated or manufactured into a liposome core, and are of the general formula wherein R 1 is an n-alkyl group of chain length C 8 -C 18 ; R 2 and R 3 are CH 3 or n-alkyl group of chain length C 2 -C 8 and X - is an anion such as halides, sulfates, nitrates, nitrites and mixtures thereof.
  • An alternate embodiment of this invention provides for a method for controlling other bacterial species, or infection carrying protozoa, including but not limited to those that result in amoebic dysentery, malaria, Giardiasis, Trichomoniasis, Cryptosporidiosis and other pathogenic protozoa.
  • the biocide containing liposomes or microcapsules can be used in a troubleshooting or proactive measure, by treating non-infected aqueous systems to be ready to attack as soon as the infected protozoa begin to appear in infective numbers.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Dentistry (AREA)
  • Pest Control & Pesticides (AREA)
  • Plant Pathology (AREA)
  • Toxicology (AREA)
  • Engineering & Computer Science (AREA)
  • Agronomy & Crop Science (AREA)
  • Wood Science & Technology (AREA)
  • Zoology (AREA)
  • Environmental Sciences (AREA)
  • Medicinal Preparation (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Micro-Organisms Or Cultivation Processes Thereof (AREA)

Description

    Field of the Invention
  • The field of the invention relates to methods for controlling protozoa trophozoites that carry or harbor bacteria in aqueous systems. More particularly, embodiments of the present invention relate to methods for controlling bacteria engulfed within protozoa in the amoeboid form, including the bacterium Legionella pneumophila.
    • Background of the Invention
  • Intracellular bacterial pathogens, that is bacterial pathogens that inhabit another cell or microorganism, are a major cause of human morbidity and mortality. Evading hostile intracellular environments is one of the ways pathogens can live within a host cell, grow symbiotically or parasitically within host cells, and yet not be killed or inhibited by the host cell. These parasites have developed ways of interacting and overcoming the host cells natural defense mechanisms.
  • Legionella pneumophila, a bacterium known to cause Legionnaire's Disease and Pontiac fever in humans is a parasite of this type. While the Legionella cells can be killed readily if exposed to certain chemical agents and antibiotics, Legionella can also be found engulfed (phagocitized) within certain protozoa hosts. Legionella are often found in biofilms adsorbed to solid surfaces in, for example, water distribution systems, cooling towers, showers, aquaria, sprinklers, spas, and cleaning baths. Protozoa are natural grazers on surfaces and engulf and digest bacteria as part of their natural life cycle. In most cases, the protozoa digest these bacteria through the use of digestive enzymes in their phagosomes (digestive vacules). In the case of Legionella, however, this is not the case. The protozoa are not readily capable of degrading the engulfed Legionella cells, and in fact the Legionella grow and increase their numbers while protected within protozoa phagosomes. Legionellosis in humans can be contracted by breathing Legionella aerosols containing either the free-living bacterial cells or by inhaling aerosols of Legionella concentrated within susceptible protozoa. A Legionella control agent, therefore, must be capable of killing free-living Legionella, Legionella within protozoa, or the protozoa themselves. The agents described in this invention are capable of killing the free-living Legionella and the host protozoa. Two protozoa species capable of harboring infectious Legionella are Acanthamoeba and Tetrahymena.
  • In order to effectively control Legionella, in addition to killing the free living or protozoa an additional factor must be taken into account. Certain protozoa, particularly amoeboid forms, have evolved mechanisms for surviving in hostile environments. Examples of hostile environments are high temperature, desiccation, presence of chemical agents/antibiotics, lack of food sources, etc. Upon encountering a hostile environment, these protozoa revert to a cyst form that is very difficult to kill. The cyst form becomes much less susceptible to chemical agents that readily kill the same organism when it is in non-cyst (trophozoite) form. Introduction of a chemical control agent to eliminate Acanthamoeba can actually provide the hostile environment to which the protozoa responds by reverting to a cyst form, thereby rendering it invulnerable to the chemical agent. When the cyst contains the pathogen Legionella, the chemical agent can no longer reach the engulfed bacteria, and the chemical treatment is rendered ineffective. As an example, chlorination or bleach is considered essential to control Legionella in water distribution systems. Exposed Legionella are readily killed by low levels of free chlorine (0.2-0.5 µg/ml).
  • Infective Legionella can also be contained in Acanthamoeba phagosomes if those protozoa are present. The Acanthamoeba, sensing the chlorine presence, reverts to a cyst form, inadvertently preserving and protecting the Legionella parasites engulfed within it. The Acanthamoeba cysts treated with > 500 times (>100 µg/ml "free" chlorine) the concentration needed to kill the trophozoite forms are not killed in the cyst form. The cysts can revert to the active trophozoite form upon removal of the oxidant.
  • Currently there are no known cyst deactivating agents in commercial use at this time. Although control agents or biocides which effectively kill or treat the Legionella bacteria are known, there is no method currently in use which provides for the means to effectively introduce the biocides or control agents into the water systems where the Legionella bacteria and Legionella harboring protozoa and cysts reside. Control agents that kill the Legionella harboring protozoa provide a much needed additional tool to safeguard the health of workers and the public against the respiratory pneumonias which can result from inhalation of Legionella or Legionella-containing protozoa cysts. For example, US patent no. 6,579,859 discloses the use of phosphonium salts of the general formula (R1)3P+R2●X- wherein R1 is an alkyl group of from 1 to 8 carbon atoms, R2 is an n-alkyl group giving 8 to 20 carbon atoms and X is an anion consisting of a halide, sulfate, nitrate, nitrite, etc.
  • US patent publication no. 2005/002710 teaches the exposure of the protozoa to quaternary ammonium salts, while US patent publication no. 2005/0080142 discloses the use of guanidine or biguanidine salts to control Legionella type bacteria in the free-living state as well as when engulfed in the trophozoite form or Acanthamoeba in cyst form.
  • However, the method of introducing these agents to the Legionella bacteria has been a barrier, particularly under actually working conditions. Therefore, a need still exists for a means to take the known biocide agents, such as those cited above, and put them in contact with the Legionella bacteria in a way that is efficient and effective, and will be of commercial use.
    • Summary of the Invention
  • According to the present invention, a method of destroying protozoa trophozites is provided according to claim 1.
    • Detailed Description of the Invention
  • The present invention relates to methods for controlling protozoa trophozoites that carry or harbor bacteria in aqueous systems. More particularly, embodiments of the present invention relate to methods for controlling bacteria engulfed within protozoa in the amoeboid form, including the bacterium Legionella pneumophila.
  • Applicants' realization underlying the invention is that since the Legionella bacteria are engulfed and protected within the phagosomes of the protozoa, a Legionella killing agent, biocide, or control agent must be placed inside the protozoa, in close proximity to the Legionella cells without causing the protozoa to grow into a cyst stage. "Biocides" is intended to include, but not be limited to biocides, biocide compositions, killing agents, control agents, and combinations thereof.
  • One embodiment provides a method for controlling protozoa trophozites which comprises encapsulating a biocide, killing agent or control agent in a micro-capsule or nano-capsule, and then introducing the micro-capsule or nano-capsule into an aqueous system in effective amounts. The microcapsules or nano-capsules are produced and applied in effective sizes, that is of a size to be phagocytized by protozoa, such as from about 0.025 to about 10 microns. The micro-capsule or nano-capsule is produced such that is has an exterior composition adapted for digestion by said protozoa. Aqueous systems include, but are not limited to, water distribution systems, cooling towers, showers, aquaria, sprinklers, spas, and cleaning baths. The biocide or agent is contained within an aqueous liposome core or trapped within the hydrophobic lipid layers. Thereafter, the liposomes are introduced into an aqueous system. The liposomes are the encapsulating bodies containing the biocide, or such a biocide-containing liposomes may themselves be further encapsulated, e.g., by a thin shell of protective material. In the latter case, the shell may, for example, be compounded to provide a further, temporary protective cover for the liposome, such as a degradable skin, that enhances the lifetime of the liposome in the water system yet dissolves, decays or otherwise breaks down after a certain time, or under certain conditions, releasing the liposomes which may then act on the target organisms.
  • Effective amounts of the biocide containing microcapsule or liposome is introduced into an aqueous system containing infected protozoa. The active protozoa, the trophozoite stage, then grazes on the microcapsules or liposomes, mistaking them for bacteria cells. Once incorporated into the protozoan cells, i.e. once they have been phagocitized, the natural enzymatic breakdown of the biocide containing microcapsule or liposome by the protozoa would result in the release of the biocide, killing agent or control agent in high concentration in the protozoa, in direct proximity to the engulfed Legionella. Rapid Legionella death would then proceed. The benign surface structure of the liposome is additionally advantageous in that, unlike a traditional control agent, it should not induce cyst formation, creating more barriers to treatment. In general, the ability of encapsulated control agents to specifically be taken up by and target the protozoa, is expected to allow a relatively low concentration of treatment material to be added to a fluid system yet be more highly effective than the use of free biocide, whose efficacy depends on its level in the fluid as a whole. Effective amounts of the biocide containing microcapsule or liposome would depend on the biocide or agent incorporated therein. However effective amounts include from about 0.05 to about 500 micrograms per milliliter, or alternately about 0.1 to about 100 micrograms per milliliter.
  • This method would also lead to the destruction of the host protozoa by the biocide or agent. In the event that the protozoa are already in the cyst stage, the addition of liposomes or microcapsules prepared with bacterial cell size and suitable membrane characteristics may induce the cysts to excyst or revert to active trophozoite stage in order to take advantage of the new food source. At that point, grazing and engulfing of the liposomes by the protozoa would then occur as set forth above.
  • Liposomes, which are systems in which lipids are added to an aqueous buffer to form vesicles, structures that enclose a volume, may be manufactured by any known process. Such processes may employ, but are not limited to, injection, extrusion (for example pressure extrusion of an aqueous biocide through a porous membrane into the lipid body or vice-versa), sonication, microfluid processors and rotor-stator mixers. The biocide containing liposomes should be produced in sizes that mimic bacterial cells, from about 0.05 to about 15 µ, or alternately, about 0.1 to 10.0 µ. Similarly, the agent may encapsulated within other oil or oil-like phases by known encapsulation processes, so as to have one or more protective outer layers that define the microcapsule lifetime, delivery characteristics and use environment.
  • Any available biocide or killing agent could be used in the present methods, including, but not limited to guanidine or biguanidine salts, quaternary ammonium salts and phosphonium salts. Examples of guanidine or biguanidine salts are of the general formulas :
    Figure imgb0001
     or
    Figure imgb0002
     or
    Figure imgb0003
     wherein R, R1, R2 are independently H, C1-C20 substituted or non-substituted alkyl (linear or branched) or aryl, X is an organic or inorganic acid, n is 0-20 and z is 1-12.
  • Examples of the general formula of acceptable phosphonium salts comprises (R1)3P+R2●X- wherein R1 is an alkyl group of from 1 to 8 carbon atoms, R2 is an n-alkyl group giving 8 to 20 carbon atoms and X is an anion consisting of a halide, sulfate, nitrate, nitrite, and combinations thereof.
  • An alternative formula provides that R1 is an alkyl group having from 1-8 carbons, R2 is an n-alkyl group having 6-20 carbon groups and X- is an anion such as halides, sulfates, nitrates, nitrites and mixtures thereof. Preferably, X- is chloride, bromide, iodide, SO4 2-, and NO3 -, NO2 - or mixtures thereof.
  • Another embodiment provides R1 and R2 are hydroxyalkyl groups having from 1-4 carbons and X- is an anion such as halides, sulfates, nitrates, nitrites and mixtures thereof. Preferably, X- is chloride, bromide, iodide, SO4 =, and NO3-, NO2- or mixtures thereof.
  • Quaternary ammonium salts are another example of a biocide or agent that may be encapsulated or manufactured into a liposome core, and are of the general formula
    Figure imgb0004
     wherein R1 is an n-alkyl group of chain length C8-C18; R2 and R3 are CH3 or n-alkyl group of chain length C2-C8 and X- is an anion such as halides, sulfates, nitrates, nitrites and mixtures thereof.
  • An alternate embodiment of this invention provides for a method for controlling other bacterial species, or infection carrying protozoa, including but not limited to those that result in amoebic dysentery, malaria, Giardiasis, Trichomoniasis, Cryptosporidiosis and other pathogenic protozoa. Additionally, the biocide containing liposomes or microcapsules can be used in a troubleshooting or proactive measure, by treating non-infected aqueous systems to be ready to attack as soon as the infected protozoa begin to appear in infective numbers.

Claims (7)

  1. A method of destroying protozoa trophozoites comprising encapsulating at least a biocide or at least a biocide composition in a micro- or nano-capsule having an exterior composition adapted for digestion by said protozoa, and introducing the biocide containing micro- or nano-capsules into an aqueous system in an effective amount of from 0.05 to 500 micrograms per milliliter, comprising manufacturing a liposome which incorporates a biocide in its core.
  2. The method of claim 1, wherein said protozoa contain Legionella type bacteria.
  3. The method of claim 1, wherein the biocide is chosen from the group consisting of guanidine or biguanidine salts, quaternary ammonium salts and phosphonium salts.
  4. The method of claim 1, wherein the effective amount of the biocide introduced into the aqueous system is from 0.1 to 100 micrograms per milliliter.
  5. The method of claim 1, wherein the aqueous system is chosen from the group consisting of potable and non-potable water distribution systems, cooling towers, showers, aquaria, sprinklers, spas, pipelines, and cleaning baths.
  6. The method of claim 1 wherein the capsules are produced and applied in sizes from 0.025 to 10 microns.
  7. The method of claim 1 wherein the liposomes are produced and applied in diameter sizes from 0.025 to 10 microns.
EP08756423.3A 2007-08-08 2008-05-29 Method for controlling protozoa that harbor bacteria Active EP2184979B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/835,717 US7785478B2 (en) 2007-08-08 2007-08-08 Method for controlling protozoa that harbor bacteria
PCT/US2008/065047 WO2009020689A1 (en) 2007-08-08 2008-05-29 Method for controlling protozoa that harbor bacteria

Publications (2)

Publication Number Publication Date
EP2184979A1 EP2184979A1 (en) 2010-05-19
EP2184979B1 true EP2184979B1 (en) 2018-12-05

Family

ID=39767041

Family Applications (1)

Application Number Title Priority Date Filing Date
EP08756423.3A Active EP2184979B1 (en) 2007-08-08 2008-05-29 Method for controlling protozoa that harbor bacteria

Country Status (9)

Country Link
US (1) US7785478B2 (en)
EP (1) EP2184979B1 (en)
CN (1) CN101820752B (en)
AU (1) AU2008284230B2 (en)
CA (1) CA2695685C (en)
ES (1) ES2713082T3 (en)
PT (1) PT2184979T (en)
TW (1) TWI487673B (en)
WO (1) WO2009020689A1 (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110052655A1 (en) * 2007-08-08 2011-03-03 Wilson Kurt Whitekettle Methods and vesicles for controlling protozoa
US8784659B2 (en) 2007-08-08 2014-07-22 General Electric Company Method for controlling microbial biofilm in aqueous systems
US20100158852A1 (en) * 2008-12-22 2010-06-24 Wilson Kurt Whitekettle Method for reduction of microbes on surfaces
US20100239626A1 (en) * 2009-03-20 2010-09-23 Wilson Kurt Whitekettle Propanediol delivery systems
US20100239651A1 (en) * 2009-03-20 2010-09-23 Wilson Kurt Whitekettle Nitrilopropionamide delivery systems
US20100239650A1 (en) * 2009-03-20 2010-09-23 Wilson Kurt Whitekettle Isothiazolin biodelivery systems
US20100239627A1 (en) * 2009-03-20 2010-09-23 Wilson Kurt Whitekettle Quarternary ammonium salts delivery systems
US20100239630A1 (en) * 2009-03-20 2010-09-23 Wilson Kurt Whitekettle Phosphonium salts delivery systems
AU2010226257A1 (en) * 2009-03-20 2011-10-06 General Electric Company Biodelivery systems
US20100266525A1 (en) * 2009-04-17 2010-10-21 Wilson Kurt Whitekettle Method for removing microbes from surfaces
US20110177147A1 (en) * 2010-01-21 2011-07-21 General Electric Company Stable biocidal delivery systems
USRE49652E1 (en) 2013-12-16 2023-09-12 Qualcomm Incorporated Power saving techniques in computing devices
US9535490B2 (en) * 2013-12-16 2017-01-03 Qualcomm Incorporated Power saving techniques in computing devices

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1561901A (en) * 1975-08-06 1980-03-05 Atomic Energy Of Australia Control of insects
US4561981A (en) * 1984-01-27 1985-12-31 Characklis William G Treatment of fouling with microcapsules
US5547939A (en) * 1991-06-14 1996-08-20 The Regents Of The University Of California Broad spectrum antimicrobial compounds and methods of use
US5164096A (en) * 1991-11-01 1992-11-17 Nalco Chemical Company Biocide microencapsulation
DE19937300A1 (en) * 1999-08-06 2001-02-22 Henkel Ecolab Gmbh & Co Ohg Biofilm avoidance
US6579541B2 (en) * 2000-03-28 2003-06-17 Marantech Holding, Llc Oxidative fluorinator compounds as antimicrobials
US6811711B2 (en) * 2000-06-02 2004-11-02 Arch Chemicals, Inc. Treatment of circulating water systems
CN1369202A (en) * 2001-02-12 2002-09-18 李金龙 Dosinfecting nano active microcapsule for military material use for civil purpose now
WO2003021031A1 (en) * 2001-09-01 2003-03-13 Rhodia Consumer Specialties Limited Phosphorus compounds
US6579859B1 (en) * 2002-06-10 2003-06-17 Ge Betz, Inc. Control of protozoa and protozoan cysts that harbor legionella
AR040301A1 (en) * 2002-06-28 2005-03-23 Alza Corp EXPANSIBLE OSMOTIC COMPOSITION AND SUSPENSION FOR IMPROVED COATING
US20040254250A1 (en) 2003-06-13 2004-12-16 Whitekettle Wilson K. Control of protozoa and protozoan cysts that harbor Legionella
US20050027010A1 (en) 2003-06-13 2005-02-03 Whitekettle Wilson K. Control of protozoa and protozoan cysts that harbor legionella
WO2006085859A1 (en) * 2005-01-31 2006-08-17 Stockel Richard F Biocidal compositions
WO2007008293A2 (en) * 2005-05-24 2007-01-18 Selenium, Ltd. Selenium-based biocidal formulations and methods of use thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Also Published As

Publication number Publication date
ES2713082T3 (en) 2019-05-17
TWI487673B (en) 2015-06-11
TW200922882A (en) 2009-06-01
WO2009020689A1 (en) 2009-02-12
CN101820752B (en) 2013-09-04
US7785478B2 (en) 2010-08-31
PT2184979T (en) 2019-03-01
CA2695685A1 (en) 2009-02-12
AU2008284230A1 (en) 2009-02-12
CN101820752A (en) 2010-09-01
US20090039034A1 (en) 2009-02-12
CA2695685C (en) 2016-05-24
AU2008284230B2 (en) 2013-11-14
EP2184979A1 (en) 2010-05-19

Similar Documents

Publication Publication Date Title
EP2184979B1 (en) Method for controlling protozoa that harbor bacteria
US20110052655A1 (en) Methods and vesicles for controlling protozoa
US8784659B2 (en) Method for controlling microbial biofilm in aqueous systems
CN102803153B (en) Stable biocidal delivery systems and treatment against biofouling
ES2643947T3 (en) Method to suppress microbial biofilms in aqueous systems
US20100239627A1 (en) Quarternary ammonium salts delivery systems
US20130259953A1 (en) Biocidal aldehyde composition for oil and gas extraction
AU2010226257A1 (en) Biodelivery systems
AU2003247415B2 (en) Control of protozoa and protonzoan cysts that harbor Legionella
EP3583074A1 (en) Pool water desinfection
US20120114728A1 (en) Biodelivery systems
AU2004273780B2 (en) Control of protozoa and protozoan cysts that harbor Legionella
CA2528059A1 (en) Control of protozoa and protozoan cysts that harbor legionella

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20100308

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20140618

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

RIC1 Information provided on ipc code assigned before grant

Ipc: A01N 57/20 20060101ALI20180221BHEP

Ipc: A01N 47/44 20060101ALI20180221BHEP

Ipc: A01P 1/00 20060101ALI20180221BHEP

Ipc: A01N 33/12 20060101ALI20180221BHEP

Ipc: A01N 25/28 20060101AFI20180221BHEP

GRAJ Information related to disapproval of communication of intention to grant by the applicant or resumption of examination proceedings by the epo deleted

Free format text: ORIGINAL CODE: EPIDOSDIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

INTG Intention to grant announced

Effective date: 20180326

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTC Intention to grant announced (deleted)
INTG Intention to grant announced

Effective date: 20180504

GRAJ Information related to disapproval of communication of intention to grant by the applicant or resumption of examination proceedings by the epo deleted

Free format text: ORIGINAL CODE: EPIDOSDIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTC Intention to grant announced (deleted)
INTG Intention to grant announced

Effective date: 20180710

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 1071885

Country of ref document: AT

Kind code of ref document: T

Effective date: 20181215

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602008058205

Country of ref document: DE

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: BL TECHNOLOGIES, INC.

REG Reference to a national code

Ref country code: PT

Ref legal event code: SC4A

Ref document number: 2184979

Country of ref document: PT

Date of ref document: 20190301

Kind code of ref document: T

Free format text: AVAILABILITY OF NATIONAL TRANSLATION

Effective date: 20190225

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20181205

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1071885

Country of ref document: AT

Kind code of ref document: T

Effective date: 20181205

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190305

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190305

REG Reference to a national code

Ref country code: BE

Ref legal event code: PD

Owner name: BL TECHNOLOGIES, INC.; US

Free format text: DETAILS ASSIGNMENT: CHANGE OF OWNER(S), CESSION; FORMER OWNER NAME: BL TECHNOLOGIES, INC.

Effective date: 20190215

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2713082

Country of ref document: ES

Kind code of ref document: T3

Effective date: 20190517

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190405

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602008058205

Country of ref document: DE

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

26N No opposition filed

Effective date: 20190906

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190531

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190529

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190529

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20080529

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20181205

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 15

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230521

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: PT

Payment date: 20230503

Year of fee payment: 16

Ref country code: IT

Payment date: 20230519

Year of fee payment: 16

Ref country code: FR

Payment date: 20230525

Year of fee payment: 16

Ref country code: ES

Payment date: 20230601

Year of fee payment: 16

Ref country code: DE

Payment date: 20230530

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20230529

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20230529

Year of fee payment: 16